A clampdown on flyposting could hit farmers' markets.

Organisers of the markets in west Oxfordshire have been told they will be prosecuted for putting up roadside signs, advertising the monthly events in Witney, Woodstock, Charlbury and Chipping Norton.

Now they are "playing by the book" and seeking planning permission for the 2ft sq signs, which are tied by string to street furniture.

They would only be put up once a month for a maximum of three days at a time - the same as they have in fact been doing for the past 18 months, with the agreement of Oxfordshire County Council's highways department.

But planning for the signs is the responsibility of West Oxfordshire District Council and, despite it promoting the markets, it looks likely it will refuse permission.

Pete Williams, of the Thames Valley Farmers' Market Co-operative, said: "We're playing it by the book, even though it's costing us over £1,000 to put in these applications for each town.

"They are only up for two days, once a month. In a recent survey, 70 per cent of people said they came along to the markets because they had seen the signs.

"If we can't put them up, we will obviously lose trade."

In Witney, the markets have gone from strength to strength, with 28 stallholders now taking part, compared with 16 a few years ago.

The markets were actually set up by the district council to support local farmers in the aftermath of the 2001 foot and mouth epidemic.

But the council is now engaged in a war against flyposting and, according to cabinet member for the environment David Harvey, that is what the market organisers have been doing by putting up their signs.

Mr Harvey said: "If we allow them to do it, it makes it extremely difficult for us to prosecute Joe Bloggs for putting up roadside signs for an all-night rave.

"The markets are a commercial concern and we don't allow it. The only signs we allow are for local charities or non-profit-making events, put up for a few days and then removed.

"That's why we told them to apply for planning permission."

The first two applications, for Charlbury and Chipping Norton, come before the council uplands planning sub-committee on Monday.

Planning officer Jonathan Westerman is urging refusal because of the precedent it would set.

He also said the number of signs, at a total of 25 roadside sites, were far too many.

Charlbury and Chipping Norton town councils both back the farmers' markets.

Stallholder Robert Power, of Heath House Nursery, in Finstock, said: "Lack of signage is bound to decrease takings, so making the farmers' markets less viable.

"This may well affect the number of stalls and the eventual stopping of the markets."